American Crew anti-dandruff shampoo: what to know

Check the package rather than relying on the product name because ingredients and directions can differ by formula or market. Follow its contact-time and frequency instructions, and stop if it causes marked irritation.

Dandruff causes loose scalp flakes and may come with mild itching. Seborrheic dermatitis can present with itch, inflammation and greasy or dry scale around the scalp, hairline, eyebrows, ears or sides of the nose.

An anti-dandruff formula may contain an ingredient that reduces yeast activity, loosens scale or limits its build-up. The front label alone does not reveal which action applies, so read the active-ingredient panel and warnings.

Wet the scalp, distribute the shampoo at the roots and use your fingertips without scratching. Leave it on only for the label's stated contact time, rinse thoroughly and keep it away from the eyes and broken skin.

Track whether flaking, itch and redness settle across several washes. Avoid layering multiple medicated scalp products at once unless a clinician recommends it, as irritation can make the original problem harder to judge.

If the hair feels dry, apply a plain conditioner mainly to the lengths rather than coating an oily or inflamed scalp.

Seek medical review for thick adherent scale, significant redness, scalp pain, pus, open sores, patchy hair loss or symptoms spreading beyond typical dandruff areas. Persistent flaking can also reflect psoriasis, eczema, contact dermatitis or a fungal infection requiring different care.

Stop using the product and get prompt help if swelling, widespread hives or breathing difficulty develops. Wash it off and arrange advice for severe burning or blistering.

Bring the bottle or a clear ingredient photo. Ask whether the scalp pattern looks like dandruff or another condition, how often to use the active ingredient, whether to alternate shampoos and what treatment is appropriate for inflamed skin outside the scalp.